How Varying Enzyme Concentrations Affect Absorbance Over Time in Potato Homogenate Mixture
Haille Armstrong
November 17, 2015
Biology 155 Laboratory-Tuesdays 6pm
Lab Partners: Kayla, Morel, Ryan
Abstract
Saturation of substrates was a phenomenon that was observed in Part II of the experiment. This was referenced from later in the discussion. When the enzyme activity from this experiment was compared to Enoch’s work, (Enoch) it was stated that he found that in certain liver cells of rats, enzyme activity would stop suddenly. The study proposed that the lower Enoch dropped the substrate concentration within these cells, the less activity he could record. This proved to both his data and to the date from this experiment that the substrate was necessary for catalysis, because as enzyme concentration rose, substrates bound more quickly to the active site of an enzyme. Once all substrates in the mixture were changed to products, the enzyme was stationary because it had no more substrate to catalyze. This meant that in order for the reaction to continue, substrate concentration had to increase.
Introduction
To understand how and why the experiment was performed, one must understand what enzymes and substrates are. Enzymes are defined as proteins that are capable of speeding up a chemical reaction by reducing the amount of activation energy needed to catalyze that reaction (Raven, Johnson and Mason 2014). Enzymes regulate these biochemical processes
Background and Introduction: Enzymes are proteins that process substrates, which is the chemical molecule that enzymes work on to make products. Enzyme purpose is to increase the rate of activity and speed up chemical reaction in a form of biological catalysts. The enzymes specialize in lowering the activation energy to start the process. Enzymes are very specific in their process, each substrate is designed to fit with a specific substrate and the enzyme and substrate link at the active site. The binding of a substrate to the active site of an enzyme is a very specific interaction. Active sites are clefts or grooves on the surface of an enzyme, usually composed of amino acids from different parts of the polypeptide chain that are brought together in the tertiary structure of the folded protein. Substrates initially bind to the active site by noncovalent interactions, including hydrogen bonds, ionic bonds, and hydrophobic interactions. Once a substrate is bound to the active site of an enzyme, multiple mechanisms can accelerate its conversion to the product of the reaction. But sometimes, these enzymes fail or succeed to increase the rate of action because of various factors that limit the action. These factors can be known as temperature, acidity levels (pH), enzyme and/or substrate concentration, etc. In this experiment, it will be tested how much of an effect
Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is
The time in the water bath was also controlled to ensure that the enzymes were left to react for the same amount of time, making the experiment
Enzymes are a key aspect in our everyday life and are a key to sustaining life. They are biological catalysts that help speed up the rate of reactions. They do this by lowering the activation energy of chemical reactions (Biology Department, 2011).
Hypothesis: If the concentration of the substrate is increased, then the rate of enzyme activity will decrease. This is because as the concentration of the substrate increases, there is an increasing amount of occupied active sites at any given moment. This will cause a decrease in the rate of enzyme activity as substrate-active site collisions are increasingly slowed down thus bringing down the rate of enzyme activity.
Enzymes are biological catalysts that speed up chemical reactions, without being used up or changed. Catalase is a globular protein molecule that is found in all living cells. A globular protein is a protein with its molecules curled up into a 'ball' shape. All enzymes have an active site. This is where another molecule(s) can bind with the enzyme. This molecule is known as the substrate. When the substrate binds with the enzyme, a product is produced. Enzymes are specific to their substrate, because the shape of their active site will only fit the shape of their substrate. It is said that the substrate is complimentary to their substrate.
In this lab we learned about what influences enzyme activity. We learned many terms and concepts in this lab. Enzymes decreases the amount of energy needed in a reaction. Catalyst speeds up reaction. A substrate is what the material with which catalyst reacts. A product is the modification of the substrate. This was a very informative and good lab.
Used to see if the temperature of the water is at 37oc – 40oc and if
Enzymes are proteins that act as catalysts and help reactions take place. In short, enzymes reduce the energy needed for a reaction to take place, permitting a reaction to take place more easily. Some enzymes are shape specific and reduce the energy for certain reactions. Enzymes have unique folds of the amino acid chain which result in specifically shaped active sites (Frankova Fry 2013). When substrates fit in the active site of an enzyme, then it is able to catalyze the reaction. Enzyme activity is affected by the concentrations of the enzymes and substrate present (Worthington 2010). As the incidence of enzyme increases, the rate of reaction increases. Additionally, as the incidence of substrate increases so does the rate of reaction.
To study the effects of temperature, pH, enzyme concentration, and substrate concentration there were certain steps that were followed in order to conduct this experiment. Each factor had a separate procedure to follow to find how each had a different effect on the enzyme.
An Enzyme is a protein, which is capable of starting a chemical reaction, which involves the formation or breakage of chemical bonds. A substrate is the surface or material on or from which an organism lives, grows, or obtains its nourishment. In this case it is hydrogen peroxide. This lab report will be explaining the experiment held to understand the effects of the changes in the amount of substrate on the enzyme’s reaction.
Organisms cannot rely entirely on spontaneous reactions to produce all the materials necessary for life. These reactions occur much too slowly. To produce these materials quicker, cells rely on enzymes, biological catalysts, to speed up these reactions without being consumed. (General Biology I, Martineau, Dean, Gilliland, & Soderstrom, Lab Manual, 2017, 43). To produce these materials quicker, the activation reaction much be lowered, a very important part of this lab. Each enzyme acts on a specific molecule, or set of molecules, called a substrate (43). The enzyme binds to this substrate, forming an enzyme-substrate complex. An enzyme is a protein whose structure is determined by the sequence of amino acids groups that
The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.
In this lab or experiment, the aim was to determine the following factors of enzymes: (1) the effects of enzymes concentration the catalytic rate or the rate of the reaction, (2) the effects of pH on a particular enzyme, an enzyme known and referred throughout this experiment as ALP (alkaline phosphate enzyme) and lastly (3) the effects of various temperatures on the reaction or catalytic rate. Throughout the experiment 8 separate cuvettes and tubes are mixed with various solutions (labeled as tables 1,3 & 4 in the apparatus/materials sections of the lab) and tested for the effects of the factors mentioned above (concentration, pH and temperature). The tubes labeled 1-4 are tested for pH with pH paper and by spectrophotometer, cuvettes 1a-4a was tested for concentration and cuvettes labeled 1b-4b was tested for temperature in four different atmospheric conditions (4ºC, 23ºC, 32ºC and 60ºC) to see how the enzyme solution was affected by the various conditions. After carrying out the procedures the results showed that the experiment followed the theory for the most part, which is that all the factors work best at its optimum level. So, the optimum pH that the enzymes reacted at was a pH of 7 (neutral), the optimum temperature that the reactions occurs with the enzymes is a temperature of 4ºC or
An enzyme is a catalyst. Catalysts are known for speeding up the rate of reactions by lowering the activation energy of the biochemical reaction. (Reece et al., 2011)